Turkey’s relationship with the European Union has been “poisoned”, its ambassador to Brussels has said, on the eve of a major report which is widely expected to offer little prospect of it joining the 28-member bloc.

In unusually frank comments for a diplomat, Selim Yenel said the relationship was beset by “a lot of mistrust, frustration, disillusionment and disappointment”.

In June, the EU agreed to reopen accession talks with Turkey but Ankara has been pinning its hopes on a positive assessment in the progress report the Commission will release on Wednesday.

The report is expected criticise the Turkish government´s violent response to public protests in the summer.

The Commission is likely to reduce Turkey´s chances of restarting accession talks, by not issuing a recommendation.

Plans to end a three-year break in accession negotiations were put on hold after countrywide anti-government protests were crushed.

Although Ankara presented some reforms last month, EU officials say the Commission will limit itself to merely welcoming the measures.

This year has marked a low point in EU-Turkey relations with planned talks on regional policy being scrapped because of the way the Turkish government handled the protests.

“The fact that we are not moving on the accession process is poisoning and disturbing the rest of the relationship,” Mr Yenel said.

Speaking to Europolitics magazine, he cautioned: “If the EU wants to become a global player beyond the economic and trade areas, it will need Turkey.”

A recent poll says less than half of Turks favour EU accession. In 2004, a similar poll found that three out of four endorsed membership.

Mr Yenel said Turkey was “fine” if accession never happened, adding: “It is no big deal. We are not like the other countries. We have options. We can survive alone.”

Turkey’s relationship with the EU is in stark contrast to what is expected to be a Commission call for a number of Balkan countries.

Member states will be asked to allow Serbia, Kosovo, Albania, Macedonia and, possibly, Bosnia to take the next steps on the road to membership.

In the cases of Albania and Serbia, this will be to launch accession negotiations formally. Kosovo’s target would be a stabilisation and association agreement (SAA). A positive report on Bosnia by the Commission could lead, within months, to an SAA signed with the EU in 2008 taking effect.